Studies On Mechanical Properties Of Brick Masonry - Core
STUDIES ONMECHANICAL PROPERTIESOF BRICK MASONRYPeri Raghava Ravi TejaDepartment of Civil EngineeringNational Institute of Technology RourkelaRourkela – 769 008, India
Studies on Mechanical PropertiesofBrick MasonryThesis submitted in partial fulfillmentof the requirements for the degree ofMaster of Technology (Research)inStructural EngineeringbyPeri Raghava Ravi Teja(Roll No. 613CE1006)under the supervision ofDr. Pradip SarkarandDr. Robin Davis P.Department of Civil EngineeringNational Institute of Technology RourkelaRourkela – 769 008, IndiaAugust 2015
Dedicated toMy Grandfather, Parents & Supervisors.
Department of Civil EngineeringNational Institute of Technology RourkelaRourkela-769 008 , Odisha , India.www.nitrkl.ac.inCertificateThis is to certify that the work in the thesis entitled “Studies on MechanicalProperties of Brick Masonry” by Peri Raghava Ravi Teja, bearing RollNumber 613CE1006, is a record of an original research work carried out by himunder our supervision and guidance in partial fulfillment of the requirementsfor the award of the degree of Master of Technology (Research) in StructuralEngineering, Department of Civil Engineering. The content of this thesis, in fullor in parts, has not been submitted to any other Institute or University for theaward of any degree or diploma.Research GuidesRourkela-769008Date:Prof. Pradip SarkarProf. Robin Davis P.Department of Civil Engineering
AcknowledgementA research work requires the support of many people directly or indirectly. I wouldlike to utilize this opportunity to convey my gratitude to all those people who havesupported and blessed me during my research work.First and foremost I would like to thank my supervisors; Prof. Pradip Sarkar andProf. Robin Davis P., for their constant support, encouragement and guidancethroughout my research programme at NIT Rourkela. I would always cherish themoments I spent with my supervisors discussing about the research findings. Theyare the source of inspiration for me, their hard work, patience, time managementand many other skills make them a true definition of a supervisor. I feel extremelyproud and thank the almighty for making me their student. I could not ask for abetter guide than them.I would like to thank Prof. S. K. Das and Prof. K. C. Biswal for the suggestionsand interest they provided in my research work.I would like to thank myMSC members, faculty of civil engineering department and structural engineeringlaboratory staff of NIT Rourkela for their support.I wish to express my sincere gratitude to Prof. S. K. Sarangi, Director, NITRourkela for giving me the opportunities and facilities to carry out my researchwork.I would like to convey my heartfelt thanks to my friends and research scholars:Sharmili Routray, Subhashree Behera, Sambit Beura, Rupalika Dash, PranabKumar Ojha, Srikar Potnuru, Kirti Kanta Sahoo and Pratik Kumar Dhir forhelping me in various ways to complete the research work.Above all, very special thanks to my family; I cannot express in words my gratitudeto my Father, Mother and Sister for their continuous support, motivation, prayersand blessings because of which I am able to complete and present this thesis.Peri Raghava Ravi Teja
AbstractKeywords: Brick masonry; water absorption; initial rate of absorption; compressive strength;variability; probability distribution function; shear bond strengthBrick masonry, a composite of brick units bound together with mortar, is widelyused for building construction in India. Burnt clay bricks are commonly usedin construction of masonry structures since many years.But with growingenvironmental concern for conservation of natural resources and disposal of flyash, bricks made with fly ash are emerging as a substitute to burnt clay bricksfor construction of masonry structures. The behaviour of masonry structure isdependent on the properties of its constituents such as brick units and mortarseparately and together as a unified mass. Brick properties vary largely fromregion to region as bricks are made with locally available raw materials withinherent randomness.Therefore, the analysis and design of brick masonrystructures considering the mean values of material properties may underestimateor overestimate the structural capacity. In order to design a safer structure itis necessary to take in to consideration the randomness and variability of thematerial properties of brick masonry. This requires mathematical description ofthe variability in different material properties of brick masonry. The variability ofmechanical properties related to steel and concrete is well researched, while thesame for brick masonry has not received proper attention. The lack of data hasled to ignorance of uncertainty in brick masonry while analysing structures.Under lateral loads, brick masonry is expected to undergo in-plane andout-of-plane forces. Resistance to out-of-plane forces in masonry structure isnegligible and generally ignored in analysis and design. However, the in-planeforces which act parallel to the plane of wall is resisted by the bond between brickand mortar. Shear bond strength of masonry plays an important role in dealingwith in-plane forces. The soaking of bricks prior to construction is very essentialto achieve good shear bond strength. Bricks with higher initial rate of absorptionmust be pre-wetted prior to use in construction else they absorb more water from
mortar inhibiting its hydration. But, the optimum duration of pre-wetting or theoptimum moisture content of brick necessary to obtain higher shear bond strengthis not available in published literatures.In present study, several experiments are carried out to determine mechanicalproperties such as initial rate of absorption, water absorption, dry density andcompressive strength of brick units, compressive strength of mortar and masonryprism and shear bond strength of masonry triplet. Higher order analyses such asX-ray diffraction and field emission scanning electron microscopy are conducted tounderstand the morphological and microstructural differences in brick leading tovariation in its compressive strength. Three different types of failure patterns suchas vertical splitting, diagonal shear failure and crushing are identified for masonryprism under axial compression.The variability in the mechanical properties of brick masonry and itsconstituent materials is described using different probability distribution functions.Four two-parameter distribution functions namely normal, lognormal, gamma andWeibull distribution are chosen and their acceptability is evaluated using threegoodness-of-fit tests such as Kolmogorov-Sminrov, Chi-square and log-likelihoodtest. All the distributions are found to be closely competing to fit the variabilitybest. Lognormal is found to be common distribution function to best describethe variability for most of the mechanical properties studied. Weibull and gammadistributions are found to be most appropriate for other properties. However,in general, gamma distribution is found to be either the best or the next bestdistribution function to describe most of the mechanical properties studied.Therefore, lognormal or gamma distribution is recommended as the distributionfunction that best describe the variability of properties of brick masonry and itsconstituents.The morphological and microstructural analyses attributed the low and highstrength in brick samples to the absence of certain chemical compounds andvariation in surface texture. The presence of compounds of silica, aluminium,calcium, iron oxide and magnesium is observed to be helpful for bricks in attaininghigher compressive strength.vi
Simple mathematical equations are proposed to estimate the compressivestrength of brick unit and masonry prism. The equations can be used for bothclay and fly ash bricks. The proposed equations are validated by comparing thepredicted value of the compressive strength with experimental value obtained frompublished literatures.The optimum moisture content in bricks at the time of construction to obtainhigher shear bond strength is experimentally determined. It is observed from thefailure pattern of triplets that shear bond failure depends on the strength of brick,mortar and their bond. IRA and moisture content of brick control the modes offailure indirectly through shear bond strength.vii
t of FiguresxiiList of TablesxviAbbreviationsxviiiNotationsxix1 Introduction11.1Background and Motivation . . . . . . . . . . . . . . . . . . . . . .11.2Objectives of the Thesis . . . . . . . . . . . . . . . . . . . . . . . .41.3Scope of the Study . . . . . . . . . . . . . . . . . . . . . . . . . . .51.4Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61.5Organisation of the Thesis . . . . . . . . . . . . . . . . . . . . . . .72 Literature Review92.1Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92.2Structural Properties of Brick Masonry9. . . . . . . . . . . . . . .2.2.1Clay Brick Masonry. . . . . . . . . . . . . . . . . . . . . . 102.2.2Fly Ash Brick Masonry . . . . . . . . . . . . . . . . . . . . . 13viii
2.3Variability in Properties of Concrete . . . . . . . . . . . . . . . . . 162.4Morphological and Microstructural Study on Clay and Fly Ash Bricks 192.5Shear Bond Strength of Brick Masonry . . . . . . . . . . . . . . . . 222.6Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 Experimental Work263.1Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263.2Materials Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263.33.43.2.1Brick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273.2.2Sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293.2.3Cement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Test Specimens Preparation . . . . . . . . . . . . . . . . . . . . . . 293.3.1Brick Units . . . . . . . . . . . . . . . . . . . . . . . . . . . 303.3.2Mortar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303.3.3Masonry AssemblagesDetailed Experimental Tests and Procedures . . . . . . . . . . . . . 333.4.13.4.23.5. . . . . . . . . . . . . . . . . . . . . 31Tests for Mechanical Properties . . . . . . . . . . . . . . . . 333.4.1.1Initial Rate of Absorption . . . . . . . . . . . . . . 333.4.1.2Water Absorption and Dry Density . . . . . . . . . 343.4.1.3Compressive Strength . . . . . . . . . . . . . . . . 353.4.1.4Shear Bond Strength . . . . . . . . . . . . . . . . . 35Tests for Morphology and Microstructure . . . . . . . . . . . 363.4.2.1X-ray Diffraction . . . . . . . . . . . . . . . . . . . 363.4.2.2Field Emission Scanning Electron Microscopy . . . 36Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384 Variability and Analytical Study on the Properties of Bricks andits Masonry394.1Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394.2Variability in Mechanical Properties of Bricks . . . . . . . . . . . . 404.2.1Variation in different Properties of Brick Units . . . . . . . . 40ix
4.3Variation in IRA . . . . . . . . . . . . . . . . . . . 424.2.1.2Variation in WA . . . . . . . . . . . . . . . . . . . 434.2.1.3Variation in dry density . . . . . . . . . . . . . . . 444.2.1.4Variation in compressive strength of brick units . . 454.2.2Variation in Compressive Strength of Mortar4.2.3Variation in Compressive Strength of Masonry Prisms . . . . 474.2.4Probability Distribution of Parameters . . . . . . . . . . . . 50. . . . . . . . 454.2.4.1IRA of Brick Units. . . . . . . . . . . . . . . . . 524.2.4.2WA of Brick Units . . . . . . . . . . . . . . . . . . 524.2.4.3Dry Density of Brick Units . . . . . . . . . . . . . 534.2.4.4Compressive Strength of Brick Units . . . . . . . . 534.2.4.5Compressive Strength of Mortar . . . . . . . . . . . 624.2.4.6Compressive Strength of CB Prism . . . . . . . . . 624.2.4.7Compressive Strength of FAB-I Prism . . . . . . . 674.2.4.8Compressive Strength of FAB-II Prism . . . . . . . 67Morphology and Microstructure of Bricks . . . . . . . . . . . . . . . 724.3.14.3.24.44.2.1.1Interpretation from XRD Analysis . . . . . . . . . . . . . . . 724.3.1.1XRD of Brick units. . . . . . . . . . . . . . . . . 724.3.1.2XRD of different grades of Mortar . . . . . . . . . 75Interpretation from FESEM Images. . . . . . . . . . . . . 77Analytical Modelling of Brick Properties . . . . . . . . . . . . . . . 804.4.1Modelling of Brick Compressive Strength . . . . . . . . . . . 804.4.2Statistical inferences for Predicted Compressive Strength ofBrick units . . . . . . . . . . . . . . . . . . . . . . . . . . . . 864.4.3Estimation of Masonry Prism Compressive Strength . . . . . 904.5Failure Pattern in Masonry Prism . . . . . . . . . . . . . . . . . . . 954.6Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 985 Shear Bond Strength of Brick Masonry1015.1Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1015.2Lacunas in Past Researches . . . . . . . . . . . . . . . . . . . . . . 102x
5.3Salient Features of Present Study . . . . . . . . . . . . . . . . . . . 1035.4Specifications of the Experimental Work . . . . . . . . . . . . . . . 1035.5Discussion of Test Results . . . . . . . . . . . . . . . . . . . . . . . 1055.6Optimum Brick Moisture Content . . . . . . . . . . . . . . . . . . . 1115.7Bond Strength and Compressive Strength of Brick Masonry5.8Failure Patterns in Triplets . . . . . . . . . . . . . . . . . . . . . . . 1165.9Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1196 Summary and Conclusions. . . . 1151206.1Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1206.2Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1216.3Main Contribution of the Research . . . . . . . . . . . . . . . . . . 1246.4Scope for Future Work . . . . . . . . . . . . . . . . . . . . . . . . . 124Appendices126A Introduction to Fly Ash Bricks126B Probability Distributions and Goodness-of-Fit Tests136C Correlation of Brick Properties142Bibliography148
List of Figures1.1Multi storey building constructed using fly ash bricks . . . . . . . .23.1Typical burnt clay brick . . . . . . . . . . . . . . . . . . . . . . . . 273.2Fly ash: (a) Source-I and (b) Source-II . . . . . . . . . . . . . . . . 283.3FAB-I type fly ash brick . . . . . . . . . . . . . . . . . . . . . . . . 283.4FAB-II type fly ash brick . . . . . . . . . . . . . . . . . . . . . . . . 293.5CM1, CM2 and CM3 grade mortar cubes . . . . . . . . . . . . . . . 313.6Typical stack-bonded masonry prism specimen . . . . . . . . . . . . 323.7Typical stack bonded masonry triplet specimen . . . . . . . . . . . 333.8Test setup for determining IRA . . . . . . . . . . . . . . . . . . . . 343.9Compression test of (a) brick (b) mortar cube and (c) prism specimen 353.10 Test setup of shear bond strength test with triplet specimen . . . . 363.11 Multipurpose X-ray diffraction system (Rigaku ULTIMA IV) . . . . 373.12 FESEM (Nova Nano SEM/FEI ) . . . . . . . . . . . . . . . . . . . 374.1Mean IRA values for three brick variants . . . . . . . . . . . . . . . 434.2Mean WA values for three brick variants . . . . . . . . . . . . . . . 444.3Mean dry density values for three brick variants . . . . . . . . . . . 454.4Mean compressive strength values for three brick variants . . . . . . 464.5Mean compressive strength for three mortar grades . . . . . . . . . 464.6Mean compressive strength of the masonry prisms . . . . . . . . . . 494.7Experimental and assumed cumulative probability distributions forIRA of brick units . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58xii
4.8Experimental and assumed cumulative probability distributions forWA of brick units . . . . . . . . . . . . . . . . . . . . . . . . . . . . 594.9Experimental and assumed cumulative probability distributions fordry density of brick units . . . . . . . . . . . . . . . . . . . . . . . . 604.10 Experimental and assumed cumulative probability distributions forcompressive strength of brick units . . . . . . . . . . . . . . . . . . 614.11 Experimental and assumed cumulative probability distributions forcompressive strength of three mortar grades . . . . . . . . . . . . . 644.12 Experimental and assumed cumulative probability distributions forfor CB prism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 664.13 Experimental and assumed cumulative probability distributions forfor FAB-I prism. . . . . . . . . . . . . . . . . . . . . . . . . . . . 694.14 Experimental and assumed cumulative probability distributions forfor FAB-II prism . . . . . . . . . . . . . . . . . . . . . . . . . . . . 714.15 XRD pattern for CB (a) low strength (b) high strength. . . . . . 734.16 XRD pattern for FAB-I (a) low strength (b) high strength . . . . . 744.17 XRD pattern for FAB-II (a) low strength (b) high strength. . . . 754.18 XRD pattern for mortar of three grades (a) CM1 (b) CM2 (c) CM3 764.19 FESEM images of CB . . . . . . . . . . . . . . . . . . . . . . . . . 794.20 FESEM images of FAB-I . . . . . . . . . . . . . . . . . . . . . . . . 794.21 FESEM images of FAB-II . . . . . . . . . . . . . . . . . . . . . . . 794.22 Variation of (a) IRA (b) WA (c) dry density with compressivestrength for FAB-I . . . . . . . . . . . . . . . . . . . . . . . . . . . 824.23 Correlation of (a) IRA (b) WA (c) dry density with compressivestrength for FAB-I . . . . . . . . . . . . . . . . . . . . . . . . . . . 844.24 Variation plot between actual and predicted compressive strengthfor FAB-I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 854.25 Predicted and assumed cumulative probability distributions forcompressive strength of brick units . . . . . . . . . . . . . . . . . . 894.26 Experimental versus Estimated prism strength for CB . . . . . . . . 924.27 Experimental versus Estimated prism strength for FAB-I . . . . . . 92xiii
4.28 Experimental versus Estimated prism strength for FAB-II . . . . . . 924.29 Vertical splitting failure in (a) CB (b) FAB-I and (c) FAB-II prisms 964.30 Fig. 4.30: Diagonal shear failure in (a) CB (b) FAB-I and (c)FAB-II prisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 964.31 Crushing failure in (a) CB (b) FAB-I and (c) FAB-II prisms . . . . 974.32 Failure due to crushing of brick . . . . . . . . . . . . . . . . . . . . 975.1Triplet before shear bond strength test . . . . . . . . . . . . . . . . 1065.2Triplet after shear bond strength test . . . . . . . . . . . . . . . . . 1065.3Shear bond strength for Set-A triplets5.4Shear bond strength for Set-B triplets . . . . . . . . . . . . . . . . . 1095.5Shear bond strength for Set-C triplets . . . . . . . . . . . . . . . . . 1105.6Shear bond strength for Set-D triplets5.7Variation in shear bond strength with moisture content of CB at the. . . . . . . . . . . . . . . . 107. . . . . . . . . . . . . . . . 111time of construction (Saturation moisture content of CB 16.69%) 1125.8Variation in shear bond strength with moisture content of FAB-Ibrick at the time of construction (Saturation moisture content ofFAB-I 16.80%) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1135.9Variation in shear bond strength with moisture content of FAB-IIbrick at the time of construction (Saturation moisture content ofFAB-II 16.84%). . . . . . . . . . . . . . . . . . . . . . . . . . . 1145.10 Relation between shear bond strength and compressive strength ofmasonry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1155.11 Failure within the brick-mortar interface (Type A) . . . . . . . . . . 1175.12 Failure within the mortar joint (Type B) . . . . . . . . . . . . . . . 1175.13 Fig. 5.13: Failure within the brick unit (Type C) . . . . . . . . . . 1185.14 Combination of failure within the brick unit and mortar joint (TypeD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118A.1 Various modes of utilization of fly ash [1] . . . . . . . . . . . . . . . 130A.2 Batching of raw materials using wheel barrow . . . . . . . . . . . . 133A.3 Mixing of raw materials in a mixer . . . . . . . . . . . . . . . . . . 134xiv
A.4 Moulding of bricks in a hydraulic press . . . . . . . . . . . . . . . . 135A.5 Air curing of fly ash bricks . . . . . . . . . . . . . . . . . . . . . . . 135B.1 KS test plot showing deviation between observed and hypothesizesCDF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140C.1 Variation of (a) IRA (b) WA (c) dry density with compressivestrength for CB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143C.2 Variation of (a) IRA (b) WA (c) dry density with compressivestrength for FAB-II . . . . . . . . . . . . . . . . . . . . . . . . . . . 144C.3 Correlation of (a) IRA (b) WA (c) dry density with compressivestrength for CB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145C.4 Correlation of (a) IRA (b) WA (c) dry density with compressivestrength for FAB-II . . . . . . . . . . . . . . . . . . . . . . . . . . . 146C.5 Variation plot between actual and predicted compressive strengthfor CB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147C.6 Variation plot between actual and predicted compressive strengthfor FAB-II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
List of Tables3.1Mix proportions and dimensions of brick specimens . . . . . . . . . 293.2Designation and mix proportions of different grades of mortar . . . 303.3Dimensions of masonry assemblages for three brick variants4.1Values of IRA, WA, dry density and compressive strength for brick. . . . 32specimens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414.2Compressive strength (MPa) for three mortar grades . . . . . . . . 474.3Compressive strength (MPa) for masonry prisms . . . . . . . . . . . 484.4Estimated parameters of distributions, KS distances, CS and LKvalues for IRA(kg/m2 /min) of brick units . . . . . . . . . . . . . . . 544.5Estimated parameters of distributions, KS distances, CS and LKvalues for WA(%) of brick units . . . . . . . . . . . . . . . . . . . . 554.6Estimated parameters of distributions, KS distances, CS and LKvalues for dry density(kN/m3 ) of brick units . . . . . . . . . . . . . 564.7Estimated parameters of distributions, KS distances, CS and LKvalues for compressive strength (MPa) of brick units . . . . . . . . . 574.8Estimated parameters of distributions, KS distances, CS and LKvalues for compressive strength(MPa) of mortar . . . . . . . . . . . 634.9Estimated parameters of distributions, KS distances, CS and LKvalues for compressive strength(MPa) of CB prism . . . . . . . . . . 654.10 Estimated parameters of distributions, KS distances, CS and LKvalues for compressive strength(MPa) of FAB-I prism . . . . . . . . 684.11 Estimated parameters of distributions, KS distances, CS and LKvalues for compressive strength(MPa) of FAB-II prismxvi. . . . . . . 70
4.12 Correlation coefficients (Cr ) among the properties of brick units . . 834.13 Coefficients for the equation to evaluate the brick strength . . . . . 854.14 Comparison of past experimental results with predicted compressivestrength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 874.15 Estimated parameters, KS Distances, CS and LK values forpredicted compressive strength (MPa) of brick units. . . . . . . . 884.16 Comparison of distribution models for experimental and predictedcompressive strength values of brick units . . . . . . . . . . . . . . . 904.17 Proposed equation for each of the three brick variant . . . . . . . . 914.18 Proposed equation for bricks based on its material . . . . . . . . . . 934.19 Comparision of past experimental results with predicted prismstrength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 944.20 Most appropriate statistical distribution functions for differentmechanical properties of bricks . . . . . . . . . . . . . . . . . . . . . 994.21 Most appropriate statistical distribution functions for compressivestrength of different grades of mortar . . . . . . . . . . . . . . . . . 994.22 Most appropriate statistical distribution functions for compressivestrength of brick masonry . . . . . . . . . . . . . . . . . . . . . . . 995.1Pre-wetting time (in minutes) for different sets of masonry triplets . 1055.2Mean shear bond strength (in MPa) for Set-A triplets . . . . . . . . 1075.3Mean shear bond strength (in MPa) for Set-B triplets . . . . . . . . 1085.4Mean shear bond strength (in MPa) for Set-C triplets . . . . . . . . 1095.5Mean shear bond strength (in MPa) for Set-D triplets . . . . . . . . 110A.1 Chemical requirements of fly ash. . . . . . . . . . . . . . . . . . . 128A.2 Physical requirements of fly ash . . . . . . . . . . . . . . . . . . . . 129
AbbreviationsASTM:American Society for Testing and MaterialsCB:Clay BrickCDF:Cumulative Distribution FunctionCM1:Cement Mortar (with Cement to Sand ratio 1:6)CM2:Cement Mortar (with Cement to Sand ratio 1:4.5)CM3:Cement Mortar (with Cement to Sand ratio 1:3)COV:Coefficient of VariationCS:Chi-SquareEDS:Energy Dispersive SpectroscopyFAB-I:Fly Ash Brick (with Fly Ash from Source-I)FAB-II:Fly Ash Brick (with Fly Ash from Source-II)FESEM:Field Emission Scanning Electron MicroscopyIRA:Initial Rate of AbsorptionIS:Indian StandardKS:Kolmogorov-SminrovLK:Log LikelihoodPDF:Probability Density FunctionSD:Standard DeviationSEM:Scanning Electron MicroscopyWA:Water AbsorptionXRD:X-Ray Diffractionxviii
NotationsEnglish Symbolsa:Constant coefficient to predict compressive stength of brick unitb:Constant coefficient of initial rate of absorptionc:Constant coefficient of water absorptionCr:Correlation Coefficientd:Constant coefficient of dry densityD:Dry density of the brick in kN/m3fb:Compressive strength of brick in MPaf'b:Predicted compressive strength of brick in MPafk:Predicted compressive strength of prism in MPafm:Compressive strength of Mortar in MPaI:Initial rate of absorption in kg/m2 /minK:Constant coefficient to predict compressive stength of prismW:Water absorption in %Greek Symbolsα:Power constant of compressive strength of brickβ:Power constant of compressive strength of mortarχ:Moisture content of brick in %ν:Standard error of estimatexix
Chapter 1Introduction1.1Background and MotivationHousing is one of the basic requirements for human survival. Masonry is aninevitable component of housing.Among different types of masonries, brickmasonry is one of the most widely used in our country and elsewhere becauseof low cost, easy availability of raw materials, good strength, easy constructionwith less supervision, good sound and heat insulation properties, and availabilityof manpower. Brick masonry is a composite material of systematic arrangementof brick units and mortar joints. The behaviour of masonry is dependent onthe properties of its constituents such as brick units and mortar separately andtogether as a unified mass. Burnt clay bricks are widely used around the globe butin recent years many other varieties of bricks have been developed. Among themfly ash bricks has gained much popularity because of its numerous advantages overburnt clay bricks.A number of heavy engineering industries in our country are responsible forhuge production of fly ash. It is found to be a challenge for the management tostore the fly ash without polluting the environment. Around 143 thermal powerstations consume nearly 500 million tons of coal and produce as much as 173million tons of fly ash every year in our country [1]. One of the best ways forsafe disposal of fly ash is to use in production of bricks. The government too1
Chapter 1Introductionemphasizes on the use of fly ash as building material in different constructionfields. Of the total amount of fly ash utilized till 2014, around 13% is used inbricks production and this trend is expected to escalate up. Use of fly ash replacingclay in making bricks, saves vast acres of land from erosion. As fly ash bricks arehydraulic pressed, the use of fossil fuels for burning clay bricks is also eliminatedthus reducing global warming. Apart from environmental benefits, fly ash brickshave structural advantages like low cost, high compressive strength, accuracy inshape and size, high strength to weight ratio, zero efflorescence and consumptionof less mortar decreasing the overall cost of construction. Recently many multistoreyed buildings are constructed with fly ash brick masonry infill owing to goodperformance and low cost. With these benefits it is inevitable that fly ash brickswould soon replace clay bricks in building constructions. Fig. 1.1 presents a typicalmulti-storeyed framed building at Rourkela, India constructed using fly ash bricksas infill wallFigure 1.1: Multi storey building constructed using fly ash bricksA lot of research efforts on burnt clay bricks are reported in literatures whilerecently researchers have started giving attention to fly ash bricks because of itsimportance as building material. However, more research on this building material2
Chapter 1Introductionis required to cope with the recent changes coming in building design philosophy.Randomness and variability of material properties can considerably affectstructural performance and safety [2]. In contradiction to reality, this phenomenonis usually neglected in conventional structural analysis and design that assumedeterministic values of material properties. This assumption makes the analysismodels less realistic and less satisfactory. With the advancement of computingfacilities, the complex structural analyses including the probabilistic nature of thevarious parameters of the structure are not difficult and have become essentialfor its response against natural loads like earthquake, wind, etc. The probabilitydistribution of various properties
Therefore, the analysis and design of brick masonry structures considering the mean values of material properties may underestimate or overestimate the structural capacity. In order to design a safer structure it . mechanical properties related to steel and concrete is well researched, while the same for brick masonry has not received proper .
and properties of materials A simple introduction to amorphous and crystalline structure was presented This was followed by some basic definitions of stress, strain & mechanical properties The mechanical properties of soft and hard tissue were then introduced Balance of mechanical properties is key for design.
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which result in anisotropic mechanical properties. The objective of this project is to investigate the anisotropic mechanical properties, crystallographic texture, and microstructure of crept zirlo materials. The anisotropic mechanical properties were investigated using uniaxial and biaxial creep tests.
4.13 Model properties for 276 tex, 3 yarns/cm with difference weave pattern 77 4.14 Model properties for 276 tex, 5 yarns/cm with difference weave pattern 78 4.15 The mechanical properties of difference weave pattern with yarn size 276 tex and yarn density 3 yarns/cm 91 4.16 The mechanical properties of difference weave pattern
Mechanical Properties Tensile and Shear properties Bending properties Time dependent properties . Tensile and Shear properties Types of forces that can be applied to material: a) Tensile b) Compressive c) Shear d) Torsion . Tensile
The Mechanical Foundation Series is a compulsory basic course for mechanical majors. It covers a wide range of courses, including mechanical drawing, mechanical principles, mechanical design, mechanical manufacturing foundation, engineering materials and tolerance technology measurement [1]. It is a learning
ASTM D 3379 ASTM D 4018 Fiber properties from test of UD laminate Property (100%) Property 100 V f 3/32. Test of laminates Tests of Sandwich Construction Monitoring of Composite Construction Mechanical testing of fiber Mechanical properties test of matrix Mechanical testing of lamina Mechanical properties test of matrix TensionASTM D 638 F tu m, F ty m, E t m, t m, "m Compression ASTM D 695 .
applications. This study is based on finding the mechanical properties and stress analysis of Graphene platelets. Here, the change in mechanical properties of epoxy nanocomposite with Graphene platelets at nano-fillers volume fraction of 0-0.112 was found. The mechanical properties measured were elastic
